Title: Aucun titre de diapositive
1Imagine a tool for generating HTML style
sheets with an interactive genetic
algorithm based on genes frequencies N.
Monmarché, G. Nocent, M. Slimane, G. Venturini,
Laboratoire d Informatique - University of
Tours, France P. Santini Alderan S.A., France
2Overview
- The problem
- Genetic algorithm gene frequencies
- HTML and style sheets
- Imagine
3The problem
- Designing the look of web pages
- Limitations of actual software
- user must define everything
- Proposed improvements
- to suggest several different look
- that will satisfy the user
4Genetic algorithms (1/4)
Short overview
- inspired from natural selection
- one solution one individual
- part of solution a gene
- select the fittest individuals, create offspring
with crossover and mutation
5GAs (2/4)
Standard crossover and mutation operators
Crossover
Mutation
6GAs (3/4)
Non standard GA based on gene frequencies
Gene n1
Value
Frequency
x
50
b
50
Gene n2
Value
Frequency
t
100
Etc.
7GAs (4/4)
Non standard operators
Selection
Mutation
8HTML style sheets
- HTML General language for text description
- Text is structured
- Example
ltBODY BGCOLORFF0000gt background color is
red. ltH1gt Large title lt/H1gt ltH6gt Small
title lt/H6gt ltFONT FACETimesgt A typical text
lt/FONTgt lt/BODYgt
9HTML style sheets (CSS)
- Aim more homogeneous look of web with a
precisely defined style
- HTML characteristics can be modified by the CSS
10Imagine
Aim to personalize one or several web pages by
optimizing the style sheet with an interactive GA
Algorithm main principles 1) Generate initially
a population of style sheets (one sheet one
individual, one gene one entry in the style
sheet), 2) Display the style sheets (apply them
to the user HTML pages and show the result
different versions of the user s pages) 3) Let
the user select the versions of his pages that he
favors 4) Update the gene frequencies according
to the selected individuals, 5) Generate the next
population, 6) Go to 2) or Stop if the user is
satisfied.
11Imagine
Genetic representation
Genes (26) Possibles Values Background (color
or image) 128 colors or 64 gif/jpeg
files Rules/bars 25 gif/jpeg files Bullets
       Titles level 1 (2 and 3)
color 128 alignment left, right, centered,
justified font 35 fonts style normal,
italic, oblique weight light, normal,
bold, Paragraph (font, style, ) Text of
introduction () Comments ()
12Imagine
More interactions
- user can directly modify the style of a page
(and modifications are taken into account in the
GA)
- Imagine manages a databases of colors, images
(Gif/Jpeg files) in order to let the user
add/remove possible gene values (and may adapt
them to his domain)
13Imagine software
Internal organisation
Color and image database
JET engine (Access)
APIs Win32
Graphics
Visual Basic
GASim.dll (Visual C)
Browser IE4 / 5
User interface
GA
Appearance of style sheets
14Conclusion and future work
- Imagine intuitive tool that optimizes HTML
style sheets in interaction with the user - GA could optimize other kind of document styles
(Word, ) - Real world implementation in progress at Alderan
S.A.